Ophthalmic phototherapy device and associated treatment method

ABSTRACT

An ophthalmic phototherapy device and associated phototherapy treatment method for promoting healing of damaged or diseased eye tissue. The ophthalmic phototherapy device includes a light emitting mechanism for transmitting light of at least one preselected wavelength to the eye tissue. The ophthalmic phototherapy method includes directing light of at least one wavelength for a selected period of time to a portion of damaged or diseased eye tissue, whereby the light transmitted to the damaged or diseased eye tissue stimulates cellular activity in the eye tissue to promote healing.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. application Ser. Nos.15/050,484, 15/050,483, and 15/050,482, filed Feb. 23, 2016, each ofwhich is a Continuation of U.S. application Ser. No. 13/679,557, filedNov. 16, 2012; which is a Continuation-In-Part of U.S. application Ser.No. 12/172,697, filed Jul. 14, 2008; which is a Continuation-In-Part ofU.S. application Ser. No. 11/858,351, filed Sep. 20, 2007 and issued asU.S. Pat. No. 7,479,136 on Jan. 20, 2009; which is aContinuation-In-Part of U.S. application Ser. No. 11/106,416, filed Apr.14, 2005.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

BACKGROUND OF THE INVENTION

1. Field of Invention

This invention relates to an ophthalmic phototherapy device and anassociated treatment method. More specifically, the present invention isrelated to a device and method for exposing an eye to selectedwavelengths of light to promote the healing of damaged or diseased eyetissue.

2. Description of the Related Art

Light has various uses within the medical community. Exposure ofcellular tissue to light is known to modulate the activity of suchcellular tissue. Different wavelengths of light act on differentmechanisms within individual cells within the cellular tissue tostimulate or suppress biological activity within the cells in a processcommonly referred to as photobiomodulation. In certainphotobiomodulation applications, commonly known as light therapy orphototherapy, the different wavelengths are used to promote healing,revitalize and rejuvenate cells, and in some circumstances, stimulatecellular regeneration and regrowth.

Molecules like cytochrome-C oxidase, hemoglobin, myoglobin, andnicotinamide adenine dinucleotide (NADH), found in cellular tissue, arerecognized as photon acceptors and serve to initiate biochemicalcellular response to photons. Additionally, it is recognized thatcertain biologic quantum field effects result from exposing cellulartissue to photonic light and that living cells generate low levels ofphotons, called biophotons. These biophotons are non-thermal in natureand are coupled to physiological functions in the cellular tissue.Biophotons represent regulatory activity from chemical reactivity withina cell and also perform regulatory activity over a given cellular tissueto promote cell growth and differentiation, and to provide intercellularand intracellular communication, such as for example, synchronicity inbiofunction between cells. Such biophotons within a cellular tissue canbe simulated by photonic light of one or more specific wavelengths froma source external to the cellular tissue. Such photonic light, whenexposed to the cellular tissue, results in promotion of regulatoryactivity within the cells of the exposed cellular tissue.

Thus, it is generally accepted that cell activity can be up-regulatedand down-regulated by specific wavelengths of low intensity light. Theup- and down-regulation of cell activity through photobiomodulation isused to suppress cytokines, block the matrix metalloproteinases (MMP)cascade, suppress interleukins (IL) and tissue necrosis factors, anddecreasing inflammation of cellular tissue. Photobiomodulation is alsoused to affect mitochondrial density and activity, cell proliferationand adhesiveness, and DNA and RNA production. Phototherapy has beenshown to affect vascular endothelial growth factor (VEGF) expression(both enhancement and suppression) and to protect against a wide varietyof toxins, such as chemical, ionizing, and bacteriologic toxins.

At least some of the known effects of the various wavelengths on bodytissues are as follows. Light in the yellow range (approximately 577 nmto 597 nm) has been shown to switch off collagenase production bydown-regulating MMPs and switching on new collagen production.Collagenases are enzymes that break down the native collagen that holdsanimal tissue together. Thus, use of light in the yellow range forphototherapy ultimately results in increased cohesion of cells in animaltissue. Light in the red range (approximately 640 nm to 700 nm) has beenshown to decrease inflammation in injured tissue, increase ATPproduction, and otherwise stimulate beneficial cellular activity. Lightin the blue range (approximately 405 nm to 450 nm) has been shown tokill various microorganisms. For example, light in the blue range hasbeen shown to kill the propionibacterium that causes acne by activatingthe porphyrins produced by the bacteria. Accordingly, phototherapy hasbeen utilized to treat infants for jaundice (e.g., U.S. Pat. No.6,811,563), to treat acne and other skin conditions (e.g., U.S. Pat. No.6,387,089), to treat rhinitis (e.g., U.S. Pat. No. 5,683,436), and totreat traumatic tissue injuries (e.g. U.S. Pat. No. 6,471,716).

Photobiomodulation also requires the use of light with suitableintensity, energy, and wavelengths, the combination of which allowslight of the selected wavelengths to penetrate the cellular tissue andactivate the desired cellular mechanism without significantly causingdamage to the cells. The combination of characteristics suitable forphotobiomodulation applications are distinct from those of light used inother applications. Other applications use high-energy, high-intensitylight sources, e.g., excimer lasers, that are destructive as opposed toregenerative, because the light emitted is so intense that, as the laserlight penetrates the cellular tissue, the cells become burned, melted,or otherwise destroyed. General purpose lighting, such as anincandescent light, uses low-energy light sources ranging in intensitythat is incapable of sufficiently penetrating the cellular tissue, whichresults in superficial exposure of the cellular tissue to the low-energylight and, therefore, reduced photobiomodulation effects. Further, anincandescent light produces numerous wavelengths and the wavelengths arenot subject to independent control, which results in unpredictablemodulation of the cellular activity within the exposed cellular tissue.High-intensity light of sufficient energy to properly penetrate thecellular tissue and initiate photobiomodulation tends to burn and/ormelt the cellular tissue prior to the completion of a phototherapytreatment. Hence, light appropriate for use in phototherapy shouldexhibit both a relatively low intensity, so as not to destroy theexposed cells, and a relatively high energy, so as to allow forsufficient penetration of light into the exposed cellular tissue suchthat the activities of a desired portion of cells within the exposedcellular tissue are photobiomodulated.

One device which is known to produce relatively low-intensity,high-energy light suitable for use in phototherapy is the light-emittingdiode (LED). Several commercial phototherapy devices are availableincluding devices which utilize LEDs, including the Gentlewaves® LEDPhotomodulation Device manufactured by Light BioScience, LLC, whichincludes a panel of LEDs for treating skin conditions, and the Flip4Max7 LED device which incorporates an LED panel capable of producingmultiple wavelengths of light, and which is also marketed for treatingskin conditions. Further, the U.S. military and NASA have utilized smallhand-held devices incorporating LED arrays that are used to reduceinflammation and to promote healing in damaged skin tissue. Light fromsuch LED devices has been shown to exhibit the low-intensity andhigh-energy characteristics appropriate for use in photobiomodulation.

Various laser devices have been used in the field of ophthalmology forthe purposes of ablating and cutting eye tissue during laser-assistedsurgery on an eye. Likewise, various laser devices have been used tomelt or otherwise liquefy eye tissue surrounding a surgical wound inorder to establish a weld or other such seal in the surgical wound.These destructive uses of light cause other damage to the eye tissue,but this other damage is of the type that can be healed by the body'snormal recuperative mechanisms over time. In addition, a device usingLEDs has been utilized in the field of ophthalmology in an effort tostrengthen corneal tissue. However, this device utilizes LEDs producingwavelengths falling in the middle to far ultraviolet ranges(approximately 100 nm to 300 nm) to induce cross-linking of cornealcollagen and thereby stiffen the cornea of the eye. Thus, this process,in effect, ages the corneal tissue, as opposed to facilitating theproduction of new, “normal” tissue. Therefore, the process is not one inwhich healing of eye tissue is promoted. Accordingly, none of the knownphototherapy mechanisms are used for promoting the healing, regrowth, orregeneration of damaged or diseased eye tissue or for alleviatingdiscomfort associated with damaged or diseased eye tissue within thefield of ophthalmology.

BRIEF SUMMARY OF THE INVENTION

The present invention provides an ophthalmic phototherapy device, and anassociated phototherapy method, for promoting healing of damaged eyetissue. The ophthalmic phototherapy device includes a light emittingmechanism for transmitting light of at least one preselected wavelengthto the damaged eye tissue, whereby the light transmitted to the eyetissue stimulates activity in the eye tissue to promote healing. Thelight emitting mechanism can include a light panel having a plurality oflight emitting diodes (LEDs) for emitting light. In one embodiment thedevice has a first set of LEDs capable of emitting light having a firstwavelength, and at least a second set of LEDs capable of emitting lighthaving a second wavelength. Further, a controller is provided forselectively controlling which LEDs are energized at any given time, suchthat different sequences and/or combinations of light wavelengths can beselectively communicated to the eye tissue being treated.

The ophthalmic phototherapy method of the present invention includesidentifying a treatable portion of cellular tissue in an eye. Theidentified portion of damaged eye tissue is exposed to light of at leastone preselected wavelength for a preselected period of time tophotobiomodulate cellular activity in the cellular tissue to promotehealing. Further, in one application of the method, the tissue isexposed to light of a plurality of wavelengths either sequentially, orin combination. In certain embodiments, the tissue is exposed to acontinuous beam of light; in certain embodiments, the tissue is exposedto a pulsing beam of light; and in certain embodiments, the tissue isexposed to a sequential combination thereof.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The above-mentioned features of the invention will become more clearlyunderstood from the following detailed description of the invention readtogether with the drawings in which:

FIG. 1 is a perspective view of an ophthalmic phototherapy deviceconstricted in accordance with several features of the present generalinventive concept:

FIG. 2 is a front elevation view of an ophthalmic phototherapy device ofFIG. 1;

FIG. 3 is a perspective view of another embodiment of an ophthalmicphototherapy device constructed in accordance with several features ofthe present general inventive concept;

FIG. 4 is a side elevation view of another embodiment of an ophthalmicphototherapy device, showing the ophthalmic phototherapy device mountedon a slit lamp;

FIG. 5 is a block diagram of a power/control system for an ophthalmicphototherapy device;

FIG. 6 is a flow diagram showing one embodiment of a method according tothe present general inventive concept;

FIG. 7 is a flow diagram showing another embodiment of the method of thepresent general inventive concept;

FIG. 8 is a flow diagram showing another embodiment of the method of thepresent general inventive concept;

FIG. 9 is a flow diagram showing several additional operationsassociated with the diagnosis operation of the method shown in FIG. 8;and

FIG. 10 is a flow diagram showing another embodiment of the method ofthe present general inventive concept;

DETAILED DESCRIPTION OF THE INVENTION

An ophthalmic phototherapy device is illustrated generally at 10 in thedrawings. As will be discussed in detail below, the ophthalmicphototherapy device 10 produces light of a selected wavelength, orsequences or combinations of light having differing wavelengths within aparticular range of wavelengths. In accordance with the ophthalmictreatment method of the present invention, the light emitted by thephototherapy device 10 is directed into the eye of a patient to promotehealing of damaged or diseased eye tissue.

FIG. 1 illustrates one embodiment of the ophthalmic phototherapy device10. The ophthalmic phototherapy device 10 incorporates a light emittingmechanism that includes a light panel 12 incorporating a plurality oflight sources 14 that emit light having the desired wavelengths. Thelight panel 12 is mounted in a housing 16 that is configured tofacilitate use of the device 10. A switch 20 allows the operator tocontrol the production of light. In one embodiment, the light sourcesare LEDs. It will be appreciated that other mechanisms capable ofemitting light of a desired wavelength, intensity, and energy can beused, and that the use of the term LEDs 14 throughout the application isnot intended to limit the available mechanisms for producing the desiredlight. For example, the light emitting mechanism could include a lowpower laser source for generating light of the appropriatewavelength(s), or one or more filtered incandescent or fluorescentlights. In the illustrated embodiment, the ophthalmic phototherapydevice 10 is configured for hand-held use. However, those skilled in theart will recognize that the ophthalmic phototherapy device can be eitherhand-held or mounted on an operatively associated medical device orother supporting structure without departing from the scope and spiritof the present invention.

FIG. 2 is a front elevation view of the phototherapy device 10. Withrespect to the particular LEDs used in the panel 12, and as will bediscussed further below, one approximate range of wavelengths desirablefor ophthalmic phototherapy is between 300 nm and 1000 nm. However,other wavelengths may be beneficial for certain applications. Thus,depending on the particular therapeutic application, the panel 12 can beconfigured to have a plurality of LEDs 14 that produce the samewavelength of light within a desired range, or the panel 12 canincorporate selected combinations of LEDs 14 capable of producing lightof differing wavelengths within a desired range. As will be discussedfurther below, where selected combinations of LEDs 14 are used whichproduce different wavelengths, the operator of the device 10 can selectamong wavelengths to be emitted within a desired range. Alternatively,where the ability to select between the wavelengths of the light emittedis desired, the panel 12 could incorporate LEDs 14 that produce a commonwavelength and conventional filters (not shown) could be used to alterthe wavelength to that desired.

In FIG. 3 an alternate embodiment of the ophthalmic phototherapy deviceof the present invention is illustrated at 10′. It will be noted thatfeatures of the device 10′ that are common to the device 10 arereferenced with common prime numerals. Those skilled in the art willrecognize that certain hand-held ophthalmic instruments, such asretinoscopes and ophthalmoscopes, utilize interchangeable, detachablehandles which incorporate rechargeable batteries. The ophthalmicphototherapy device 10′ includes a housing 16′ that detachably coupleswith such an interchangeable, rechargeable battery handle 22. Thus, thedevice 10′ utilizes a power supply which is commonly available toophthalmic health care professionals, and does not require a rechargingsystem that is unique to the phototherapy device.

A further alternate embodiment of the ophthalmic phototherapy device ofthe present invention is illustrated at 10″ in FIG. 4. In this regard,it will be noted that features of the device 10″ that are common to thedevice 10 are referenced with common double prime numerals. Asillustrated, the ophthalmic phototherapy device 10″ includes anarticulated arm 24 that allows the device 10″ to be adjustably mountedon a piece of operatively associated ophthalmic equipment such as theillustrated slit lamp 26. Although, the device 10″ is illustrated asbeing mounted on a slit lamp 26 in FIG. 4, it will be understood thatthe device 10″ could be mounted on various other pieces of equipment orstructures. For example, and as will be discussed further below, in oneembodiment, the device 10″ is mounted proximate the head of an excimerlaser such that device 10″ can be utilized immediately before, duringand/or after laser eye surgery. In another embodiment, the device 10″ ismounted proximate an ophthalmic imaging device, such as for example anoptical coherence tomography (OCT) device, an autofluorescence imagingdevice, etc., such that the device 10″ can be utilized in conjunctionwith the ophthalmic imaging device to deliver a phototherapy treatmentto a precise area of eye tissue.

With reference to FIG. 4, whereas the articulated support arm 24 definesvarious jointed configurations which allow the device 10″ to beselectively positioned at various locations while being supported onassociated ophthalmic equipment or other structures, the illustrated arm24 includes a first arm section 28 having first and second end portions30 and 32, respectively. The first end portion 30 is pivotally securedto the slit lamp 26 or other supporting structure, such that the arm 24can be selectively pivoted in a substantially horizontal plane. Thesecond end portion 32 of the first arm section 28 is pivotally securedto the first end portion 36 of a second arm section 34 such that thesecond arm section 34 pivots in a substantially vertical plane. Further,the second arm section 34 is pivotally secured proximate its second endportion 38 to a bracket 40 provided on the housing 16″ such that thehousing 16″ and the light panel 12″ pivot in a substantially verticalplane which is substantially perpendicular to the plane in which thesecond arm section 34 pivots.

It will be recognized that various mechanisms could be used forpivotally securing the first arm section 28 to a supporting structure,for pivotally securing the first arm section 28 to the second armsection 34, and for pivotally securing the second arm section 34 to thebracket 40. However, as illustrated in FIG. 4, in one embodiment anattachment structure 42 is provided that is secured to the supportingstructure, as by an adhesive or by mechanical fasteners (not shown), anda threaded fastener 44 having a locking knob 48 is used to pivotally,and lockably, secure the first end portion 30 of the first arm section28 to the attachment structure 42. A second threaded fastener 50 havinga locking knob 52 is provided for pivotally, and lockably, securing thesecond arm section 34 to the first arm section 28, and a third threadedfastener 54, with a locking knob 56, is provided for pivotally, andlockably, securing the second arm section 34 to the bracket 40. Thus, itwill be recognized that the articulated support arm 24 allows the lightpanel 12″ to be pivoted to a position where it does not interfere withthe use of the equipment on which it is mounted, and allows the lightpanel 12″ to be pivoted into position to emit light into the eye of apatient when needed. Whereas the ophthalmic phototherapy device 10 anddevice 10′ could be used in conjunction with laser eye surgery, it willbe recognized that use of the device 10″ with its articulated supportarm 24 is particularly advantageous. In this regard, the articulatedsupport arm 24 allows the device 10″ to be mounted proximate a lasersurgery apparatus such that both immediately prior to and immediatelyfollowing the surgical procedure, the panel 12 can be rotated intoposition to emit light into the eye to promote healing.

FIG. 5 illustrates a block diagram of the ophthalmic phototherapy device10. The ophthalmic phototherapy device 10 includes a power supply 18 forenergizing the light panel 12 in response to operation of the switch 20which selectively connects and disconnects the light panel 12 and thepower supply 18 to turn the panel 12 on and off. In one embodiment, thepower supply is a battery (not shown) that is preferably rechargeable.In other embodiments, suitable circuitry is provided for connecting thedevice to a conventional AC power supply such as a wall outlet. Inaddition, as will be discussed below with respect to the phototherapymethod of the present invention, several embodiments of the ophthalmicphototherapy device 10 allow selective control of the wavelength of thelight emitted by the device 10, as well as the duration of a patient'sexposure to the light emitted, and the energy and intensity of the lightemitted. Accordingly, the ophthalmic phototherapy device 10 illustratedin FIG. 5 includes a power/control system 58 that includes a controller60 for activating and/or deactivating the LEDs. In several embodiments,the controller 60 includes a timer for automatically turning the LED'soff after a preselected period of time. The controller 60 also controlsthe energy output of the LEDs 14 and the intensity of the output light,and, where LEDs 14 emitting light of different wavelengths are used,which LEDs are lit at any given time. Further, in another embodiment thecontroller 60 allows different LEDs to be lit in a desired sequence, orin a pulsed format. In one embodiment, the controller is implemented indiscrete circuits, either analog or digital, designed to perform thevarious functions. In another embodiment, the controller is implementedusing any processor device or other similar device providing thenecessary logic and control functions.

Referring to FIG. 6, the phototherapy method 76 of the present inventionincludes generally identifying and/or diagnosing a treatable portion ofcellular tissue in an eye 62, such as a damaged and/or diseased portionof cellular tissue, or a portion of cellular tissue in which imminentdamage or disease is anticipated. Once a treatable portion of cellulartissue is identified, treatment is performed 74 by directing light of atleast one preselected wavelength to cells forming at least a portion ofthe cellular tissue to be treated. The wavelength composition of thelight directed to the cellular tissue during treatment is preselected sothat exposure of the cellular tissue to the light results inphotobiomodulation of the cellular activity of at least a portion of thecells forming the cellular tissue, such that healing of the cellulartissue is promoted.

The approximate range of wavelengths desirable for ophthalmicphototherapy correspond to portions of the visible and invisibleinfrared spectrum ranging from blue light to near-infrared and infraredlight, in other words, light having wavelengths between approximately300 nm and 1000 nm, and preferably between 490 nm and 810 nm. However,both the general and preferred ranges are not intended to be limiting aswavelengths outside of these ranges may be helpful for certain treatmentapplications. The particular wavelength used varies depending on theinjury or eye condition being treated. For example, light in the yellowrange (approximately 577 nm to 597 nm) has been shown to switch offcollagenase production by down-regulating MMP production and to switchon new collagen production. In the field of opthamology, yellow lighthaving a wavelength of approximately 590 nm has been found to bebeneficial for treating corneal trauma when directed into a traumatizedcornea. Red light (approximately 640 nm to 700 nm) has been found todecrease inflammation of tissue in the eye, increase ATP production, andreset cellular activity to cause abnormal cells to exhibit more normalbehavior. Further, a preselected sequence or combination of wavelengthscan be advantageously used in certain conditions. For example, asequence or combination of infrared or near-infrared light, red light,and yellow light directed into the eye at a dosage of approximately 4joules/sq. cm has been found to be beneficial for treating glaucoma.Similar dosages of sequences or combinations of infrared ornear-infrared light, red light, and yellow light have been found tostimulate the cells in the trabecular meshwork to produce macrophagesthat then reduce the pigment cells clogging the meshwork of the eye,thereby allowing the eye to drain.

The duration of the phototherapy treatments varies depending on theparticular eye condition being treated. Beneficial tissue response canbe obtained from dosages of less than 4 joules/sq. cm, such that theduration of treatment can be relatively short. Exposure times of lessthan one minute can be beneficial, with exposure times in excess of 10minutes being contemplated. For example, to achieve approximate dosagesof less than 4 joules/sq. cm, treatment duration could vary betweenunder a minute to approximately 10 minutes, depending upon the outputpower and intensity of the light source utilized. Further, althoughphototherapy treatments of less than 0.1 joules/sq. cm, and havingdurations of 40 seconds or less, have been shown to be beneficial,longer treatments may be desirable to provide additional benefit, or toallow for larger dosages of light energy per unit area of cellulartissue. Of course, it will be understood by one skilled in the art thatbeneficial tissue response can be obtained from dosages of light energygreater than 4 joules/sq. cm, and such dosages may be used withoutdeparting from the spirit and scope of the present invention.

FIG. 6 is a block diagram of one method 76 for promoting healing of eyetissue. In the illustrated embodiment, the method begins with awavelength selection step 78, involving the selection of one or morewavelengths of light for use in the method 76. As discussed above, theparticular wavelengths selected for use depends upon the desiredcellular activity to be stimulated through application of the method 76.For example, in one embodiment, wavelengths in the red and near-infraredspectrums are selected to suppress inflammation of the eye tissue. Inanother embodiment, wavelengths in the yellow spectrum are selected tosuppress collagenase production and to stimulate new collagenproduction. In still another embodiment, wavelengths in multiple colorspectrums are selected to stimulate multiple desired cellular activitiesin the treated eye tissue.

In a dosage selection step 80, a suitable dosage of light is selectedfor use in the method 76 for the selected wavelength. In the illustratedembodiment, selection of the dosage 80 includes selection of amount oflight energy 82 to be delivered over a selected period of time 84 at aselected intensity 86. However, it will be understood that otherfactors, such as for example the topical area of cellular tissue to betreated, diffusion of the light to be applied, and other such factors,may be selected during the selection of dosage 80 without departing fromthe spirit and scope of the present invention. A light source isprovided which is capable of generating a beam of light having thecharacteristics selected during the dosage selection step 80. At atreatment phase 74, the light source is used to generate a beam of light88 having the characteristics selected during the dosage selection step80. In the illustrated embodiment, a beam of light is generated 88having the energy, duration, and intensity characteristics selected inthe dosage selection step 80. Of course, it will be understood that theparticular characteristics of the generated beam of light depend uponthe specific factors selected during the dosage selection step 80. At adirection step 90, the beam of light 88 is directed to a portion of eyetissue to be treated. Upon exposure of cells in the eye tissue to thebeam of light 88, at least a portion of the cells are stimulated toundergo at least one desired cellular activity corresponding to theselected wavelength. In this way, cellular activity useful in promotionof healing of the eye tissue is stimulated.

In another embodiment, illustrated in FIG. 7, the method 76′ is used forpromoting healing of eye tissue both before and after performing amedical procedure on the eye to correct vision problems. In theillustrated embodiment, the method begins with an optional pretreatmentdosage selection step 92, wherein a dosage is selected for an optionalpretreatment step 72. The pretreatment step 72 involves directing lightof one or more selected wavelengths of selected energy, duration, andintensity characteristics into the cornea of the patient's eye in orderto stimulate the eye tissue to engage in cellular activity beneficial tohealing. In one embodiment, the light uses wavelengths in the red andnear-infrared spectrums to suppress inflammation of the eye tissueduring and after surgery. In another embodiment, the light used in thepretreatment step 72 uses wavelengths in both the yellow and redspectrums to suppress inflammation of the eye tissue during and aftersurgery, to suppress collagenase production, and to stimulate newcollagen production.

In a damage phase 62, a medical procedure for correcting vision problemsis performed, thereby damaging a portion of eye tissue. The medicalprocedure of the illustrated embodiment uses laser surgery of theepithelium and stroma portions of the cornea of the eye, alaser-assisted in situ keratomileusis procedure commonly referred to asLASIK eye surgery as an example. The LASIK procedure involves the step64 of cutting a flap in the epithelium of the cornea of an eye whileleaving the eye tissue at one end of the flap uncut. It will beappreciated by those familiar with LASIK that a knife, referred to as amicrokeratome, or a laser, such as the IntraLase™ femtosecond (1054 nm)laser, can be used to cut the flap 64. In a folding step 66, the uncuttissue serves as a hinge that allows the flap to be folded back toreveal the stroma, or middle section of the cornea. A reshaping step 68uses pulses from a computer controlled excimer laser to vaporize aportion of the stroma and reshape the cornea. The LASIK procedure endswith a flap replacement step 70 in which the flap of epithelium tissueis replaced 70.

To this extent, in the illustrated embodiment, the damage phase 62includes performing LASIK eye surgery on an eye. However, while theembodiment of the method in FIG. 7 illustrates the performance of lasereye surgery at the damage phase 62, it will be understood that thephototherapy method of the present invention can also be beneficiallyused to promote healing of eye tissue in connection with various othereye conditions. For example, the method 76′ is also effective inpromoting healing in connection with LASIK or Epi-Lasik procedures,corneal inlays, corneal transplants (penetrating keratoplasty or PKP),cataract and intraocular implant (IOL) surgery, and glaucoma surgery.Utilized during or after such procedures, the present phototherapymethod reduces healing time and the need for extended use ofpostoperative drugs such as steroids. Moreover, the phototherapy methodof the present invention is useful in promoting healing of damaged eyetissue whether the damage is the result of disease, accident, surgery,or other such occurrences. To this extent, in another embodiment, thedamage phase 62 is accomplished by allowing a portion of cellular tissuein an eye to become damaged or diseased.

Following the damage phase 63, a treatment dosage selection step 80 isperformed. As discussed above, selection of the treatment dosage 80includes selection of an amount of light energy to be delivered over aselected period of time at a selected intensity. In a treatment step 74,light of a selected wavelength is directed into the cornea of thepatient's eye in accordance with the selected treatment dosage 80 forphotobiomodulating the damaged eye tissue to promote healing andsuppress inflammation.

Whereas numerous wavelengths are beneficial during the optional initialstep 72, the yellow range of wavelengths (approximately 577 nm to 597nm) is particularly beneficial for treatment 74 of the eye tissue afterlaser eye surgery. Thus, in one embodiment, the light directed into thepatient's eye 72 subsequent to replacement of the epithelial flap 70 ispreselected to exhibit a wavelength in the yellow spectrum, having arange of approximately 577 nm and 597 nm. In another embodiment, thelight directed into the patient's eye 72 subsequent to replacement ofthe epithelial flap 70 is preselected to exhibit a wavelength betweenthe range of approximately 577 nm and 1000 nm. In more discreetembodiments, the light directed into the patient's eye 72 followinglaser surgery 62 is preselected to exhibit multiple wavelengths in theyellow light spectrum, having ranges of between approximately 577 nm to597 nm, and the red and near-infrared spectrum, having ranges betweenapproximately 640 nm to 1000 nm.

In another embodiment, illustrated in FIG. 8, the method 76″ is used forpromoting healing of retinal eye tissue exhibiting age-related maculardegeneration (ARMD), and in particular, the so-called “dry form” of ARMD(hereinafter “dry ARMD”). In the illustrated embodiment, the method 76″begins with an initial diagnosis step 94 wherein a condition of dry ARMDis diagnosed in a patient. In several embodiments, the diagnosis step 94is performed either through a vision test of the type known in the art,through visual examination of the patient's eye, or both. However,certain more discreet embodiments, the diagnosis step 94 is performedusing an ophthalmic imaging technique, such as for example by performingfluorescein angiography of the retina of the patient, or through use ofan ophthalmic imaging device. In certain embodiments, an opticalcoherence tomography (OCT) device of the type known to one of skill inthe art is used. More specifically and with reference to FIG. 9, in theillustrated embodiment, an OCT device is used to direct a measure oflight 96 to a retina of a patient's eye. Thereafter, the OCT devicedetects 98 the degree to which the directed light is scattered througheye tissue in the patient's eye, and such data is used to generate 100 ahigh-resolution image of the patient's retinal eye tissue. Thereafter,the image of the patient's retinal eye tissue is examined 102, whereuponthe presence of dry ARMD is confirmed, thereby diagnosing 94 the patientwith dry ARMD.

Upon diagnosis 94 of dry ARMD in a patient's eye, a treatment dosageselection step 80′ is performed as shown in FIG. 8. As discussed above,selection of the treatment dosage 80′ includes selection of an amount oflight energy having one or more wavelengths to be delivered over aselected period of time at a selected intensity. Once the treatmentdosage is selected 80′, in an optional step, an ophthalmic phototherapydevice 10 of the type discussed above may be configured 106 to generateat least one beam of light conforming to the selected treatment dosage.Alternatively, an ophthalmic phototherapy device 10 may be providedwhich is pre-configured to deliver the selected treatment dosage. In asubsequent treatment step 74′, light of the selected wavelength orwavelengths is generated 88′ and then directed 90′ into the retina ofthe patient's eye in accordance with the selected treatment dosage 80′for photobiomodulating the retinal eye tissue to promote recovery of theretinal eye tissue from the effects of dry ARMD.

It will be understood that the exact intensity, energy, and duration oflight which must be generated 88′ and directed 90′ at the patient's eyein order to deliver the selected dosage to the patient's retinal eyetissue is dependent, among other factors, upon the amount of, andtransparency or opaqueness of, any matter imposed between the ophthalmicphototherapy device 10 and the retinal tissue to be treated. Forexample, in certain embodiments in which the patient's eyelid is toremain closed during treatment 74′, light that is generated 88′ anddirected 90′ toward the patient's eye is of much higher intensity andenergy than that which is needed to accomplish the selected dosage.Thus, it is understood that the light will first pass through the closedeyelid of the patient before reaching the patient's retinal eye tissue,whereupon only a portion of the generated 88′ and directed 90′ lightwill reach the patient's retinal eye tissue, thereby accomplishingdelivery of the selected dosage to the retinal eye tissue. In otherembodiments, the patient's eyelid is to remain open during treatment74′. In these embodiments, light that is generated 88′ and directed 90′toward the patient's eye is of only slightly higher intensity and energythan that which is needed to accomplish the selected dosage. Thus, it isunderstood that the light will pass through the relatively transparentcornea, lens, and vitreous humor of the eye without losing much of itsintensity and energy, whereupon most of the generated 88′ and directed90′ light will reach the patient's retinal eye tissue, therebyaccomplishing delivery of the selected dosage to the retinal eye tissue.

Numerous selectable dosages of light phototherapy have been found to bebeneficial in the treatment 74′ of dry ARMD. In one embodiment, theselected treatment dosage comprises a plurality of different light beamsapplied in sequence to the patient's retinal tissue. For example, in theembodiment illustrated in FIG. 10, a method 76′″ is shown in which thetreatment step 74″ includes ensuring 108 that the eyelid of thepatient's eye to be treated is closed. A continuous beam of light isfirst generated 110 exhibiting a wavelength between approximately 580 nmto 680 nm, and preferably approximately 670 nm. This generatedcontinuous beam is then directed 112 to the retinal tissue of thepatient's eye through the patient's closed eyelid for approximately 80to 90 seconds to achieve an initial applied dose of approximately 4joules/sq. cm, to the patient's eyelid, with the effective dose reachingthe patient's retinal tissue through the closed eyelid and otherinterposed eye tissue being approximately 0.4 joules/sq. cm.

Following the application 112 of the continuous beam to the patient'sretina, a pulsing beam of light is generated 114. The generated pulsingbeam, in several embodiments, exhibits multiple wavelengths in the redand/or near-infrared spectrum, and exhibits a pulse rate, or duty cycle,in which the beam is turned on and off at predetermined intervals. Inseveral embodiments, the duty cycle of the pulsing beam, that is, theratio of duration that the pulsing beam is “on” versus the duration thatit is “off,” is between approximately 30% “on” and 70% “off,” andapproximately 70% “on” and 30% “off.” For example, in one embodiment, apulsing beam is generated 114 exhibiting at least a first wavelengthbetween approximately 580 nm to 680 nm, and preferably approximately 670nm, as well as at least a second wavelength between approximately 850 nmto 950 nm. In this embodiment, the pulsing beam exhibits a duty cycle ofapproximately 250 milliseconds on and 150 milliseconds off. Thegenerated pulsing beam is directed 116 to the retinal tissue of thepatient's eye through the patient's closed eyelid for approximately 35to 45 seconds, or approximately 100 cycles, to achieve an initialapplied dose of approximately 0.11 joules/sq. cm, to the patient'seyelid, with the effective dose reaching the patient's retinal tissuethrough the closed eyelid and other interposed eye tissue beingapproximately 0.01 joules/sq. cm.

It will be understood that, while the above-discussed dosage of lightphototherapy has been found to be beneficial in the promotion of healingin retinal tissue demonstrating dry ARMD, it is in no way the intentionof the applicant to limit the scope of the present general inventiveconcept to the above-discussed ranges of wavelengths and/or duty cycles.For example, in certain embodiments, a dosage is selected 80′ andapplied in the treatment step 74′ in which the pulsing beam exhibits aduty cycle of approximately 50% “on” and 50% “off.” In certainembodiments, the various wavelengths of the pulsing beam may include twoor more wavelengths in the red spectrum and/or two or more wavelengthsin the near-infrared spectrum. Furthermore, in certain embodiments,multiple ophthalmic phototherapy devices 10 may be provided to producethe various wavelengths of light comprising a given selected dosage,such that each discreet wavelength emanates from a separate ophthalmicphototherapy device, rather than a light phototherapy dosage comprisinga plurality of collimated wavelengths emanating from a single ophthalmicphototherapy device 10. Moreover, as discussed above, the specificenergy and/or intensity of light used in the treatment step 74′ may beadjusted to accommodate either an open or closed eyelid of a patient,and it is not the intention of the applicant to limit the scope of thepresent general inventive concept to methods which necessarily requireopening or closure of the patients eyelid for treatment.

In light of the above, it will be recognized that the ophthalmicphototherapy devices 10, 10′, and 10″ are particularly well suited foradministering phototherapy to the eye of a patient. It will be notedthat use of the ophthalmic phototherapy device 10″, with its articulatedsupport arm 24 (see FIG. 4), can be particularly useful in applyingphototherapy in accordance with the present method 76′ subsequent tolaser eye surgery 62. In this regard, the articulated support arm 24allows the panel 12″ to be rotated into position to emit light into thepatient's eye immediately upon completion of the surgical procedure.

While the present invention has been illustrated by description ofseveral embodiments and while the illustrative embodiments have beendescribed in considerable detail, it is not the intention of theapplicant to restrict or in any way limit the scope of the appendedclaims to such detail. Additional advantages and modifications willreadily appear to those skilled in the art. The invention in its broaderaspects is therefore not limited to the specific details, representativeapparatus and methods, and illustrative examples shown and described.Accordingly, departures may be made from such details without departingfrom the spirit or scope of applicant's general inventive concept.

The invention claimed is:
 1. A method for promoting recovery of retinaltissue in an eye of a patient exhibiting dry age-related maculardegeneration, said method comprising: delivering two or more lightdosages of different wavelengths onto retinal tissue in an eye of apatient exhibiting dry age-related macular degeneration; wherein each ofsaid two or more light dosages is of at least 10⁻² J/cm², wherein afirst light dosage of said two or more light dosages has a firstwavelength of visible light between approximately 577 nm and 597 nm anda second light dosage of said two or more light dosages has a secondwavelength of visible light between approximately 640 nm and 700 nm,wherein each of said two or more light dosages is of sufficient energydensity to modulate one or more cellular activities in said retinaltissue and to promote the recovery of said retinal tissue.
 2. The methodof claim 1 wherein at least one of said two or more light dosages isdelivered to said retinal tissue via a continuous beam of light and atleast another of said two or more light dosages is delivered to saidretinal tissue via a pulsing beam of light.
 3. The method of claim 1,further comprising: delivering a third light dosage of a thirdwavelength onto said retinal tissue, wherein said third wavelength isdifferent than the first and second wavelengths and wherein said thirdlight dosage is of a sufficient energy density to modulate one or morecellular activities in said retinal tissue and to promote the recoveryof said retinal tissue.
 4. The method of claim 3 wherein said thirdwavelength is between 490 and 810 nm.
 5. The method of claim 3 whereinsaid third wavelength is between 490 and 950 nm.
 6. The method of claim3 wherein said third wavelength is between 850 and 950 nm.
 7. The methodof claim 1 wherein said first wavelength is approximately 590 nm.
 8. Themethod of claim 1 wherein said second wavelength is approximately 670nm.
 9. The method of claim 3 wherein said third wavelength isapproximately 850 nm.
 10. The method of claim 3 wherein said firstwavelength is approximately 590 nm, said second wavelength isapproximately 670 nm, and said third wavelength is approximately 850 nm.11. The method of claim 3 wherein said second wavelength isapproximately 670 nm and said third wavelength is approximately 850 nm.12. The method of claim 3 wherein said first light dosage modulates afirst cellular activity in said retinal tissue, said second light dosagemodulates a second cellular activity in said retinal tissue, and saidthird light dosage modulates a third cellular activity in said retinaltissue.
 13. The method of claim 1 wherein each of said two or more lightdosages is delivered to said retinal tissue while an eyelid of the eyeof the patient remains open.
 14. A method for promoting the recovery ofretinal tissue in an eye of a patient exhibiting dry age-related maculardegeneration, said method comprising: directing onto said retinal tissuea continuous beam of light comprising visible light having a firstwavelength, wherein said continuous beam of light is delivered for afirst duration such that said continuous beam of light delivers a firstdosage of at least 10⁻² Joules/cm² to said retinal tissue and directingonto said retinal tissue a pulsing beam of light comprising light havinga second wavelength, wherein said pulsing beam of light is delivered fora second duration such that said pulsing beam of light delivers a seconddosage of at least 10⁻² Joules/cm² to said retinal tissue and whereineach of said first and second light beams is of sufficient energydensity to modulate one or more cellular activities in said retinaltissue and to promote the recovery of said retinal tissue.
 15. Themethod of claim 14 wherein one of said continuous and pulsing lightbeams has a wavelength of visible light between 577 nm and 597 nm andthe other of said continuous and pulsing light beams has a wavelength ofvisible light between 640 nm and 700 nm.
 16. The method of claim 14,further comprising: directing onto said retinal tissue a third beam oflight comprising light having a third wavelength, wherein said thirdwavelength is different than said first and second wavelengths andwherein said third beam of light is of a sufficient energy density tomodulate one or more cellular activities in said retinal tissue and topromote the recovery of said retinal tissue.
 17. The method of claim 16wherein said third wavelength is between 490 nm and 810 nm.
 18. Themethod of claim 16 wherein the third wavelength is between 850 nm and950 nm.
 19. The method of claim 14 wherein each of said continuous andpulsing light beams is delivered to said retinal tissue while an eyelidof the eye of the patient remains open.
 20. The method of claim 16wherein said first wavelength is approximately 590 nm, said secondwavelength is approximately 670 nm, and said third wavelength isapproximately 850 nm.